1. Field of Invention
The invention relates to a frequency division type protection device and, in particular, to a frequency division type protection device for portable information processing systems.
2. Related Art
As information technology prospers, people have more chances to encounter electronic devices. In particular, the modern society relies a lot upon computer uses. Computers are widely used in government bureaus, enterprise systems, homes and individuals. To facilitate and increase work or research efficiency, more and more people start to use portable computers with which users can process works at hand. They can be further used as notebooks, to receive or send electronic mail. When the user travels, a portable computer can allow the user to do all sorts of works to gain the optimal efficiency.
Nevertheless, portable computers often crash during uses. When this happens, the user has to turn off the computer and restart the system. Unsaved information would be lost and the user has to wait a while for the system to reboot. Currently available portable computers usually have an inverter protection circuit to determine whether the power supply functions normally. If there is any abnormal activity in the power supply, it immediately shuts down the portable computer, stopping the job of the LCM (Liquid Crystal Display Module). Again, the user has to reboot the system in this case. However, it is often the case that the circuit makes incorrect judgment or experience some noises and shuts down the LCM, resulting in the portable computer's unable to function correctly.
Obviously, the drawback of the conventional portable computers is that the inverter uses voltages for comparison. Therefore, the portable computer is often shut down in correctly due to circuit misjudgments or noise interference. It is an interesting question how to solve the above issues.